Ensure you've latest CB build release installed as there was a now fixed bug in the language finder. As with all language strings you override them from a single location and that's CBs built in language override feature shown below.
www.joomlapolis.com/blog/kyle/18701-language-overrides-have-arrived
If you can't find the language key you can translate the string word for word. Example as follows.
Key: Name on card
Text: Card Name
We also provide a language debugger within CB > Configuration > Integrations that you can turn on to see a list of language strings at the bottom of the page.
krileon
